Alternator & Regulator Mitsubishi Eclipse I

DESCRIPTION

Mitsubishi alternators are conventional 3-phase, self-rectifying type units containing 6 diodes (3 positive and 3 negative) which are used to rectify current. All models use a case-mounted Integrated Circuit (IC) voltage regulator.

Alternator relay or resistor with diode is used to ensure charging of battery even if charging indicator light is defective. (Scheme 9)-14.

ADJUSTMENTS

ALTERNATOR BELT DEFLECTION ADJUSTMENT

TROUBLE SHOOTING

Note. See TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.

ALTERNATOR TO BATTERY CONTINUITY TEST

Note. Check alternator wire harness connections and drive belt tension and ensure battery is fully charged before performing test.

Scheme 1

1. Turn ignition switch to OFF position. Disconnect negative battery cable. Remove output lead from alternator terminal "B". (Scheme 1) Install a 100-amp ammeter in series with terminal "B" and disconnected output lead. Install positive lead of ammeter to terminal "B" and negative lead to disconnected output wire.
2. Install a digital voltmeter between alternator terminal "B" and positive battery terminal. Install positive voltmeter lead to terminal "B" and negative lead to positive battery terminal. Reconnect negative battery cable.
3. Start engine. Turn accessories on and adjust engine speed until ammeter indicates 20 amps, and note voltmeter reading. If voltmeter indicates.2 volt or less, system is okay.
4. If voltage is greater than.2 volt, wiring is defective between alternator terminal "B", fusible link and positive battery terminal. Disconnect negative battery cable, and remove test equipment.

ALTERNATOR OUTPUT TEST

Note. During alternator output test, a slightly discharged battery should be used as a fully charged battery may not allow full alternator output.

1. Turn ignition switch to OFF position. Disconnect negative battery cable. Disconnect alternator output wire from terminal "B". Install positive lead of 100-amp ammeter to terminal "B" and negative lead to disconnected output lead. CAUTION: Tighten each connection securely as heavy current flow will exist. DO NOT use clips on ammeter.
2. Connect positive voltmeter lead (0-20 volts) to alternator terminal "B" and negative lead to ground. Install tachometer, and reconnect negative battery cable.
3. Ensure voltmeter indicates battery voltage. If no voltage exists, an open circuit is present in wire between alternator terminal "B" and negative battery terminal. Check grounds and fusible link.
4. Turn headlights on, and start engine. Set headlights at high beam and heater switch on HIGH. Quickly accelerate engine speed to 2500 RPM and note alternator output current on ammeter. Minimum output should be within specification. Refer to the «ALTERNATOR MINIMUM OUTPUT SPECIFICATIONS»(/mitsubishi/eclipse/i-1989-1995/remont/charging-system/#alternator-regulator) table. NOTE: Output voltage changes with electrical load and temperature. Ensure proper electrical load is applied while checking output. Nominal output may not be obtained if alternator or ambient temperature is excessive. Allow alternator or temperature to cool, and recheck output. Alternator output is stamped on metal plate attached to alternator case.
5. If minimum output is not obtained and alternator wiring is okay, repair alternator. Disconnect negative battery cable, and remove test equipment.

REGULATED VOLTAGE TEST

Note. Ensure battery is fully charged and proper drive belt tension exists.

1. Turn ignition switch to OFF position. Disconnect negative battery cable. Connect positive voltmeter lead to terminal "S" of alternator. (Scheme 1) Connect negative voltmeter lead to ground.
2. Disconnect alternator output wire from terminal "B". Install a 100-amp ammeter in series with terminal "B" and disconnected output lead. Install positive lead of ammeter to terminal "B" and negative lead to disconnected output wire. Install a tachometer, and reconnect negative battery cable.
3. Turn ignition switch to ON position and ensure voltmeter indicates battery voltage. If no voltage exists, there is an open in wire between alternator terminal "S" and positive battery terminal or fusible link is blown.
4. Start engine. Ensure all lights and accessories are off. Operate engine at 2500 RPM and read voltmeter when alternator output current drops to 10 amps or less. Voltage regulator is okay if voltage output is within specification. See «REGULATOR VOLTAGE SPECIFICATIONS»(/mitsubishi/eclipse/i-1989-1995/remont/charging-system/#alternator-regulator) table.

RECTIFIER ASSEMBLY

1. Using ohmmeter, check for continuity between diodes and stator coil lead connection. (Scheme 2) Reverse leads. If continuity exists in both directions, diode is shorted. Replace rectifier assembly.
2. To check entire diode assembly, use an ohmmeter to check for continuity between both ends of each diode. (Scheme 2) Switch ohmmeter leads. Continuity should exist in one direction only. If no continuity exists or continuity exists in both directions, diode is defective. Replace rectifier assembly.

Scheme 2

ROTOR

1. Check continuity across rotor slip rings. Resistance should be within specification. See «ROTOR RESISTANCE SPECIFICATIONS»(/mitsubishi/eclipse/i-1989-1995/remont/charging-system/#alternator-regulator) table. Replace rotor if no continuity exists or resistance is not within specification.
2. Check continuity between individual slip rings and rotor shaft. If continuity exists, rotor coil or slip ring is grounded. Replace rotor.

STATOR

Ensure no continuity exists between stator coil leads and stator core. Check continuity between leads of stator coil. If no continuity exists between coil leads, replace stator.

REMOVAL & INSTALLATION

Note. Before disconnecting battery, retrieve radio code if equipped with Anti-theft radio (Anti-Theft will be present on radio facia).

For drive belt routing information. See DRIVE BELT ROUTING & ADJUSTMENT SPECIFICATION .

Removal & Installation (DOHC)

For Alternator (Generator) removal procedures, follow numbered steps in illustration. (Scheme 3)and (Scheme 4). For Alternator (Generator) Installation Procedures, follow the numbered steps in the illustration in reverse order. Numbered steps in illustration refer to service points to observe while removing and installing Instrument Panel. Arrows pointing AWAY from each other refer to service points to be observed while performing that step of the removal procedure. Arrows pointing TOWARD each other refer to service points to be observed while performing that step of the installation procedure. More detail on specific step(s) is covered, as necessary, under Points Of Removal and/or Points Of Installation.

Scheme 3

Scheme 4

Points Of Removal

1. Step 2: Removing alternator and bracket assembly. Before removing the assembly from the engine, loosen the assembly bolt by which the alternator is fixed at the alternator bracket.
2. Step 4: Removing alternator. There is only a small amount of room in which to take out the alternator. TAKE CARE not to damage the nearby components.

Points Of Installation

1. Step 4: Installing alternator and bracket assembly. Before installing the alternator bracket to the engine, install the alternator in the engine compartment.

Removal & Installation (DOHC, Stealth & 3000GT)

For Alternator (Generator) removal procedures, follow numbered steps in illustration. (Scheme 5)and (Scheme 6). For Alternator (Generator) Installation Procedures, follow the numbered steps in the illustration in reverse order. Numbered steps in illustration refer to service points to observe while removing and installing Instrument Panel. Arrows pointing AWAY from each other refer to service points to be observed while performing that step of the removal procedure. Arrows pointing TOWARD each other refer to service points to be observed while performing that step of the installation procedure. More detail on specific step(s) is covered, as necessary, under Points Of Removal and/or Points Of Installation.

Scheme 5

Scheme 6

1. Step 3: Removing clamp nuts of A/C Suction hose On vehicles equipped with air conditioning, remove clamp nuts, carefully raise the suction hose and suspend it from the engine hood using a cord.

Removal & Installation (SOHC)

For Alternator (Generator) removal procedures, follow numbered steps in illustration. (Scheme 7) For Alternator (Generator) Installation Procedures, follow the numbered steps in the illustration in reverse order. Numbered steps in illustration refer to service points to observe while removing and installing Instrument Panel. Arrows pointing AWAY from each other refer to service points to be observed while performing that step of the removal procedure. Arrows pointing TOWARD each other refer to service points to be observed while performing that step of the installation procedure. More detail on specific step(s) is covered, as necessary, under Points Of Removal and/or Points Of Installation.

Scheme 7

1. Step 6: Removing alternator. Remove the mounting nut and bolt. Take out the alternator from the transaxle side though the bottom of the intake manifold plenum.
2. Step 6: Removing alternator. Note: There is only a small amount of room in which to take out the alternator. TAKE CARE not to damage the nearby components.

OVERHAUL

Replace brushes if worn to limit line. Limit line is line closest to rotor contact end of brush. Brushes can be retained in brush holder while installing rotor by inserting wire into back of rear housing. (Scheme 8)

Scheme 8

ALTERNATOR MINIMUM OUTPUT

ALTERNATOR MINIMUM OUTPUT SPECIFICATIONS

REGULATOR VOLTAGE

REGULATOR VOLTAGE SPECIFICATIONS

ROTOR RESISTANCE

ROTOR RESISTANCE SPECIFICATIONS

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

See also:
• TROUBLE SHOOTING - BASIC PROCEDURES
• DRIVE BELT ROUTING & ADJUSTMENT SPECIFICATION
• ALTERNATOR MINIMUM OUTPUT SPECIFICATIONS